In motorcycles of recent design, a part of a vehicle body frame is often covered with a cowl. The muffler bodies of such motorcycles are exposed from the cowl in order to improve their heat radiation properties. As the muffler body is exposed from the cowl, however, some problems arise, such as, for example, that the muffler body may be damaged or deformed by bouncing stones or other debris during running of the motorcycle. Alternatively, the muffler body can become rusted by the deposition thereon of water, such as rainwater. These problems are not readily overcome by locating the muffler body within the cowl because, if the muffler body is located inside the cowl, the possibility of heat dissipated from the muffler body remaining within the cowl becomes a problem.
It is to the solution of these problems, therefore, to which the present invention is directed.